In recent years, with the rapid development of communications technologies, an air interface throughput rate of a network has been increasing continuously; however, because a quantity of users has been increasing gradually and data services have also been growing continuously, load of a communications network is increasingly heavy, which often causes network congestion. In this case, it is difficult to ensure the user communication quality.
To relieve congestion of a communications network, a network operator chooses a data offloading manner to offload some data on a communications network to other available access technologies, so as to implement supplement to the communications network. A Wireless Fidelity (Wireless Fidelity, WiFi for short) technology is one of the access technologies. The WiFi technology is characterized by a cost-free spectrum, a high air interface throughput rate and low device costs, and therefore, by using the WiFi technology to perform data offloading, an air interface throughput rate can be greatly increased and network construction costs can be reduced.
However, in the prior art, security of data transmission between user equipment (User Equipment, UE for short) and a WiFi access point (Access Point, AP for short) is relatively low, and therefore, communication security is threatened.